Present participle; Past participle - obstructing - obstructed Present - obstruct - obstruct - obstructs - obstruct - obstruct - obstruct Past - obstructed - obstructed - obstructed - obstructed - obstructed - obstructed Future - will obstruct - will obstruct - will obstruct - will obstruct - will obstruct - will obstruct Present conditional - would obstruct - would obstruct - would obstruct - would obstruct - would obstruct - would obstruct Present Perfect - have obstructed - have obstructed - has obstructed - have obstructed - have obstructed - have obstructed Past Perfect - had obstructed - had obstructed - had obstructed - had obstructed - had obstructed - had obstructed Future Perfect - will have obstructed - will have obstructed - will have obstructed - will have obstructed - will have obstructed - will have obstructed Past conditional - would have obstructed - would have obstructed - would have obstructed - would have obstructed - would have obstructed - would have obstructed Imperative - - - obstruct - - - - - - - -